Forming apparatus for hydraulic press

ABSTRACT

In a hydraulic forming tool of the diaphragm type, the punch and the work holder or die member are rigidly mounted on separate pistons that move in communicated cylinders, so that downward movement of one effects upward movement of the other by reason of displacement of fluid from the bottom of one of said cylinders to the bottom of the other. Adequate forming force is assured by metering outflow of fluid from the upper portion of the cylinder having the upgoing piston.

United States Patent 3,636,061 PROCESS FOR THE PREPARATION OF EPOXYPHOSPHONATES Richard J. Turley, Derby, Conn., assignor to Olin Corporation No Drawing. Filed Nov. 21, 1969, Ser. No. 878,926 Int. Cl. C07f 9/38 U.S. Cl. 260348 7 Claims ABSTRACT OF THE DISCLOSURE An improved method for preparing 1,2-epoxyalkyl phosphonates useful for flame retardants in plastics, especially polyurethanes, condenses dialkyl phosphites with alphahaloketones using alkali metal alcoholates in lower aliphatic alcohols as reagent.

This invention relates to an improved method for preparing dialkyl 1,2-epoxyalkyl phosphonates by condensing dialkyl phosphites with alpha-haloketones using alkali metal alkoxides in lower aliphatic alcohols as reagent. The reaction is exemplified by the following equation:

(C2H50)2PO.H OIOHgCOCH; NaOCH (CZH50)2PO.C(\CH3)/CH2 NaCl CH OH The products have been prepared using other methods, usually in two steps and in poor yields by Arbuzov and other Russian authors. See Chem. Abstr. 51, 8001; 51, 9473; 53, 15035; 54, 24454; 59, 813 and 59, 15306. In contrast, these products are obtained by the process of this invention in better yields, better quality and in one step.

According to the process of the present invention, substantially equimolar proportions of dialkyl phosphite, alpha-haloketone and alkali metal alkoxide are mixed at room temperatures or lower, suitably zero to 35 C. in a lower aliphatic alcohol having up to 6 carbons. The instantaneous reaction is highly exothermic and cooling is usually required. Advantageously the reaction mixture is neutralized with carbon dioxide gas, precipitated salts are removed, suitably by filtration and the alcohol is removed by distillation, evaporation or dilution with water. The recovered 1,2-epoxya1kyl phosphonate is preferably distilled. Yields vary but range up to 95 percent and are improved over prior art methods.

In the process of the invention suitable dialkyl phos phites include substituted and unsubstituted dialkyl phosphites, for example, dimethyl phosphite, diethyl phosphite, diisopropyl phosphite, di-n-butyl phosphite, bis(2 ethylhexyl) phosphite, bis(2-chloroethyl) phosphite, bis- (Z-bromoethyl) phosphite and other alkyl and haloalkyl phosphites having 1 to 12 carbons in each alkyl group. Mixed alkyl phosphites and mixtures of alkyl phosphites are suitably used.

Sutiable alpha-haloketones are aliphatic or cyclo aliphatic and suitably have aromatic substituents, for example, chloroacetone, bromoacetone, 2-chlorocyclohexanone, 2-chloro-2-methylcyclohexanone, 2-chlorocyclopentanone, phenacyl chloride, phenacyl bromide, p-chlorophenacyl bromide and other alpha-haloketones having 3 to 12 carbons. Mixtures of alpha-haloketones are suitably used. The halogen is suitably chlorine or bromine.

3,636,061 Patented Jan. 18, 1972 The alkoxides of the alkali metals are used as condensing agents but sodium and potassium alkoxides are most convenient. The alkoxides of any of the saturated aliphatic alcohols having 1 to 6 carbons are suitable. Examples include sodium methoxide, sodium ethoxide, sodium isopropoxide and potassium tertiary butoxide. Suitably excess alcohol used in preparing the alkali metal alkoxide serves as reaction medium. Preferably the alkoxide is derived from the same alcohol as the dialkyl phosphite but under the mild conditions of reaction of the process of this invention there appears to be little if any interchange involving the alkyl groups of the phosphite and the use of mixtures leads to no adverse results. The alkoxide and alcohol do not necessarily have the same alkyl group.

Substantially stoichiometric proportions of 1:1:1 of dialkyl phosphite, alpha-haloketone and alkali metal alkoxide are suitably used. This is not critical and variations of 10 percent are satisfactory although yields may not be improved thereby.

The dialkyl 1,2-epoxya1kyl phosphonates are useful as such in known polyurethane foam formulations. They are non-fugitive in humid or dry heat aging of the resulting foams and permanently confer flame retardant properties. These phosphonates are also reactive with polyols, for example, glycerol, to form phosphorus and/or chlorinecontaining polyols which are advantageously incorporated as part of the polyol component of polyurethane foams.

EXAMPLE I Diethyl 1,2-epoxypropyl 2-phosphonate A well-stirred solution of 34.5 g. (0.25 mole) of diethyl phosphite and 24.0 g. (0.26 mole) of chloroaeetone in ml. of absolute ethanol was treated dropwise with a solution of sodium ethoxide in ethanol prepared from 5.7 g. (0.25 mol) of sodium metal dissolved in 125 ml. of absolute ethanol.

The reaction mixture was cooled in an ice-bath and the rate of addition of base was adjusted to maintain temperatures at 8 to 12 C. The addition of base was accompanied by a strong exotherm in the reaction mixture for the first 4 to 5 ml. The remainder of the base solution was added more rapidly. After the addition of sodium ethoxide solution was completed, the reaction mixture was stirred for 0.5 hour at room temperature. Carbon dioxide was passed through the mixture for about 15 minutes to neutralize excess base. The mixture was filtered free of precipitated salt and the filtrate was evaporated to a liquid residue. Chloroform was added to the residue and the additional precipitated salt was removed by filtration. Removal of solvent and distillation of the residue yielded 45.8 g. (94.4 percent) of colorless distillate boiling at -95 C. at 0.6 mm. pressure; 11 1.4303. The distillate was redistilled through a short Vigreux column to give 39.7 g. (81.9 percent) of an analytical sample of diethyl 1,2-epoxypropyl 2-phosphonate collected at 9394 C./0.65 mm.; n 1.4291.

Calcd. for C H O P (percent): C, 43.30; H, 7.73; P, 15.98. Found (percent): C, 43.29; H, 7.58; P, 16.01.

V.p.c. analysis of this compound showed the absence of other material. The presence of the epoxide group was indicated by absorption at 11.7 and 12.5 in the infrared spectrum. The epoxide group was further verified by the formation of the known diethyl 1-chloro-2-hydroxypropyl 2-phosphonate by reaction of the above product with hydrogen chloride in hexane solvent.

EXAMPLE II Dirnethyl 1,2-epoxypropyl 2-phosphonate A solution of sodium methoxide in absolute methanol (0.25 mole of sodium) was added dropwise to a wellstirred solution of dimethyl phosphite (0.25 mole) and chloroacetone (0.26 mole) in absolute methanol. at icebath temperature. After addition was complete, the mixture was saturated with carbon dioxide and the salt precipitate was removed by filtration. The mixture was further worked up as described in Example 1. Distillation gave a 92.3 percent yield of colorless distillate boiling at 8292 C. at 0.65 mm. Redistillation through a short glass bead packed column gave a 73 percent yield of analytically pure dimethyl 1,2-epxypropyl 2-phosphonate boiling at 85-88 C./0.6 mm., 21 1.4308.

Calcd. for C H O P (percent): C, 36.14; H, 6.63; P, 18.67. Found (percent): C, 36.42; H, 6.60; P, 18.57.

EXAMPLE III 'Diisopropyl 1,2-epoxypropyl 2-phosphonate An equimolar solution of diisopropyl phosphite and chloroacetone was treated dropwise with a solution of sodium ethoxide in ethanol at 14 C. The product of the reaction was isolated as described above to give an 87 percent yield of colorless distillate boiling at 87-95 C./0.6 mm. Redistillation through a short Vigreux column gave a 60 percent yield of analytically pure diisopropyl 1,2-epoxypropyl Z-phosphonate boiling at 93-4 C./0.6 mm.; n 1.4263.

Calcd. for 'C I-I O- P (percent): C, 48.65; H, 8.56; P, 13.96. Found (percent): C, 48.43; H, 8.41; P, 13.98.

EXAMPLE IV Di-n-butyl 1,2-epoxypropyl 2-phosphonate The procedure of Example III was repeated using equimolar amounts of di-n-butyl phosphite, chloroacetone and sodium ethoxide in ethanol as solvent. An initial 94.1 percent yield of material was obtained by a simple distillation at Ill-127 C./0.5 mm. An analytical sample of di-n-butyl 1,2-epoxypropyl 2-phosphonate was obtained in 67 percent yield by redistillation at 1256 C./0.5 mm.; n 1.4371.

Calcd. for C I-I O P (percent): C, 52.80; H, 9.20; P, 12.40. Found (percent): C, 52.94; H, 9.09; P, 12.33.

EXAMPLE V Bis(2-ethylhexyl) 1,2-epoxypropyl 2-phosphonate The procedure of Example III was repeated using equimolar amounts of di(2-ethylhexyl) phosphite, chloroacetone and sodium ethoxide in ethanol as solvent. A first distillation at 184-203 C. at 0.7 mm. gave a 66.3 percent yield of product; 11 1.4459. A subsequent careful distillation gave 35 percent yield of light yellow bis (Z-ethylhexyl) 1,2-epoxypropyl 2-phosphonate boiling at ISO-187 C./0.6 mm.; n 1.4454.

EXAMPLE VI Bis(2-ch1oroethyl) 1,2-epoxypropyl 2-phosphonate The procedure of Example III was repeated using equimolar amounts of bis(2-chloroethyl) phosphite, chloroacetone and sodium ethoxide in ethanol as solvent. Bis(2-chl0roethyl) 1,2-epoxypropy1 Z-phosphonate was obtained in a 44 percent yield as a colorless distillate boiling at 96l23 C./0.03 mm.; 11 1.4646. Redistillation afiorded material boiling at 110 C./0.03 mm.; 11 1.4672.

Calcd. for C H Cl O P (percent): CI, 27.00; P, 11.79. Found (percent): CI, 28.05; P, 11.99.

4 EXAMPLE VII Bis(2-chloroethyl) 1,2-epoxypropyl Z-phosphonate The procedure of Example VI was repeated using the equivalent amount of sodium isopropoxide in isopropanol as solvent. The yield of bis(2-chloroethyl) 1,2-epoxypropyl 2-phosphonate was 78 percent of product boiling at 107-122 C./ 0.05 mm.; 11 1.4698. Redistillation gave a light yellow product collected at 110-1 12 'C./ 0.03 mm.; 11 1.4712.

EXAMPLE VIII Repetition of the procedure of Example III using the equivalent amount of bromoacetone in place of chloroacetone yields the same diisopropyl 1,2-epoxypropyl 2- phosphonate.

EXAMPLE IX Repetition of the procedure of Example III using equivalent amounts of diisopropyl phosphite, phenacyl bromide and sodium ethoxide in ethanol yields diisopropyl l phenyl 1,2 epoxyethyl l-phosphonate.

EXAMPLE X In a typical foam formulation, 25 to 30 g., of the phosphonate additive was blended at ambient temperature with 100 g. of a 3000 molecular weight triol derived from glycerol and propylene oxide. A total of 1.5 ml. of polysiloxane polyalkylene glycol ester surfactant, 0.5 ml. of triethylene diamine catalyst and 4 ml. of water was then blended into the polyol solution. A total of 0.6 ml. of 50 percent stannous octoate catalyst was added to the mixture, then 42.5 ml. of toluene diisocyanate (an /20 mixture of the 2,4 and 2,6 isomers) was added. The isocyanate-polyol mixture was rapidly stirred for about 10 seconds. The formulation was then poured into an open box, whereupon foaming of the reaction mixture occurred. The flexible foam samples thus obtained were oven-cured at about C. for about 10 minutes, then cured further at ambient temperature for about two days. The flammability of the foams was tested as described in ASTM- D1692-59T. The following table presents the results of the flammability tests.

Results of tests It Humid Product of Example N o. Grams Unaged aged 11 20 SE 2.0 30 SE 1.5 SE 1.4 20 B 3.7

SE=Self-extinguishing: B=Burns; figures denote inches burned. 51 The humid aging was conducted at 121 C. in a steam autoclave for ours.

What is claimed is:

1. Method for preparing dialkyl 1,2-epoxya1kyl phosphonates by contacting dialkyl phosphite, alpha-haloketone and alkali metal alkoxide in solution in absolute lower aliphatic alcohol to form a reaction mixture containing dialkyl 1,2-epoxyalkyl phosphonate and separating said dialkyl 1,2-epoxya1kyl phosphonate from said reaction mixture.

2. Method as claimed in claim 1 in which the molar ratio of said dialkyl phosphite, alpha-haloketone and alkali metal alkoxide is substantially 1: 1: 1.

3. Method as claimed in claim 1 in which said reaction mixture is neutralized by introducing carbon dioxide gas, salts are separated from said reaction mixture and said dialkyl 1,2-epoxyalkyl phosphonate is separated from the resulting salt-free reaction mixture.

4. Method as claimed in claim 1 in which said dialkyl phosphite has 1 to 12 carbons in each alkyl group.

5. Method as claimed in claim 1 in which said alphahaloketone has 3 to 12 carbons and the halogen is selected from the class consisting of chlorine and bromine.

6. Method as claimed in claim 1 in which said alkoxide has 1 to 6 carbons.

7. Method as claimed in claim 1 in which said dialkyl phosphite is bis(2-chl0roethyl) phosphite, said alpha-haloketone is chloroacetone, said alkoxide is sodium ethoxide, said lower aliphatic alcohol is ethanol and said dialkyl 1,2-epoxyalkyl phosphonate is bis(2-chloroethyl) 1,2- epoxypropyl 2-phosphonate.

References Cited FOREIGN PATENTS 1,046,047 11/1958 Germany.

6 OTHER REFERENCES Bulletin of the Academy of Sciences of the USSR, Div. of Chemical Science, No. 1, January 1960, pp. 780-7. The Journal of General Chemistry of the USSR, vol. 5 27 1957 pp. 1093-6.

Houben-Weyl, Methodcn der Organischen Chemie, vol. 12/1 (1963), p. 495.

0 NORMA S. MILESTONE, Primary Examiner US. Cl. X.R.

260-25 AR, 2.5 AH, 2.5 AT, 2.5 AC 

2. cooperating with the second piston means to define, in the other end portion of said second cylinder means, a chamber which varies in volume with movement of said second piston means; and E. means providing for throttled flow of fluid from said chamber to yieldingly resist movement of said second piston means toward the resilient forming element and concomitantly resist motion of said one rigid tool part in the direction away from the resilient forming element, thereby maintaining the resilient forming elEment engaged under substantial force with a blank overlying both of said rigid tool parts.
 2. The forming apparatus of claim 1, further characterized by: one of said cylinder means and its piston means being annular and concentrically surrounding the other cylinder means.
 2. said pressurized fluid source means to provide for refilling the upper portion of the second cylinder means after a cycle of closing and opening motion of the press jaws by which a workpiece is formed, thus effecting return movement of the second piston means and concomitant return movement of the first piston means.
 2. means in fixed relation to said other jaw cooperating with said plunger to define a variable-volume pressure chamber, and
 3. means providing for throttled flow of fluid out of said variable volume pressure chamber.
 3. The forming apparatus of claim 1, further characterized by: one of said cylinder means comprising a plurality of cylinders at circumferentially spaced intervals around the other cylinder means; and B. the piston means for said one cylinder means comprising a plurality of pistons, one for each of said plurality of cylinders.
 4. The forming apparatus of claim 3, wherein said means providing for substantially free flow of fluid between the first and second cylinder means comprises means defining a plurality of passages, one connecting each of said plurality of cylinders with said other cylinder means, further characterized by: means for selectively blocking at least certain of said passages, for changing the effective volume of said one cylinder means and thereby changing the relative strokes of the tool parts.
 5. The forming apparatus of claim 1, further characterized by: A. one of said cylinder means being located below the other; B. the piston means of said one cylinder means being connected with its tool part by a substantially elongated coaxial stem; and C. the other of said cylinder means and its piston means being annular and surrounding said stem.
 6. The forming apparatus of claim 1, further characterized by: A. said means providing for throttled flow of fluid from said chamber comprising a flow-restricting device; B. means providing a source of pressurized fluid; and C. a flow-directing valve communicated with said chamber and alternatively communicable with
 7. The forming apparatus of claim 6, further characterized by: A. first control means connected with the flow-directing valve and operatively so associated with a part connected with the forming apparatus as to cause the flow-directing valve to be communicated with said pressurized fluid source means in consequence of movement of said one press jaw away from the other to its fully open position; and B. second control means connected with the flow-directing valve and operatively associated with a part that moves in unison with one of said piston means for causing the flow-directing valve to be communicated with said flow-restricting device when the first piston means attains a predetermined position in its return motion.
 8. The forming apparatus of claim 6, further characterized by: A. a pressure-responsive transducer in the upper portion of the second cylinder means for producing an output which is a function of fluid pressure therein; B. a rate-responsive transducer operatively associated with one of said tool parts for producing an output which is a function of the rate at which said tool part moves; and C. said flow-restricting device being connected with said pressure-responsive transducer and with said rate-responsive transducer and being responsive to their outputs.
 9. The forming apparatus of claim 1 wherein said resilient forming element comprises: A. a substantially cylindrical pressure chamber member having a bore therethrough and which is carried by said other jaw of the press for limited motion toward and from the same in the directions of opening and closing motions of the press; B. a plunger fixed to said other jaw of the press and sealingly slidably received in said bore in the pressure chamber member to close one end portion of the same; C. a resilient diaphragm extending across the bore in said pressure chamber member near the other end thereof and cooperating with said member and the plunger to define a pressure fluid chamber; and D. means yieldingly biasing the pressure chamber member in the direction toward said other jaw to maintain fluid in said fluid chamber under pressure.
 10. Forming apparatus for a press having a pair of jaws arranged for relative closing and opening movement, said forming apparatus being of the type comprising a resilient diaphragm carried by one jaw of the press and a pair of relatively movable rigid tool parts carried by the other jaw for cooperation with the diaphragm, one of said rigid tool parts being substantially annular and in surrounding relation to the other, said forming apparatus being characterized by: A. a substantially cylindrical pressure chamber member having a bore therethrough and which is carried by said one jaw of the press for limited axial motion toward and from the same in the directions of jaw motions, said diaphragm extending sealingly across the bore in said pressure chamber member near the end thereof remote from said one jaw; B. a plunger fixed to said one jaw and sealingly slidably received in said bore to close the other end thereof; C. means yieldingly biasing the pressure chamber member in the direction toward said one jaw to maintain fluid in said bore under pressure; D. means providing a motion-transmitting connection between said rigid tool parts whereby the force which the diaphragm exerts upon them through a blank to be formed, upon closing motion of the jaws, effects motion of one of said rigid tool parts in the direction toward said other jaw and motion of the other one in the opposite direction; and E. means for yieldingly resisting motion of the rigid tool parts in their said directions, to thereby maintain a substantially high pressure in the fluid in said bore and concomitantly maintain forming force upon a blank interposed between the diaphragm and the tool parts, the last-named means comprising
 11. The forming apparatus of claim 10, wherein said rigid tool parts have normal positions from which they are displaced in consequence of closing motion of the jaws, further characterized by: F. pump means connectable with said variable-volume pressure chamber in bypass relation to said means providing for the throttled flow of fluid therefrom, for effecting return motion of the rigid tool parts to their normal positions upon completion of a cycle of closing and opening motion of the jaws. 